Laying Low

Geographical Vulnerabilities of Coastal Living

An old church converted into two townhomes sits 60 feet above Newport Harbor, safely away from the encroaching sea.

It is here that long-time Newport residents Hilary and David Stookey moved nearly five years ago, leaving their previous home along Almy Pond, a stone’s throw from Bailey’s Beach. They sought refuge, in part, from flooding, a rising sea, and the erosion that is consuming Rhode Island shorelines—which are also sinking.

“Did climate change play a part in this? Oh, yes. Major time,” says Hilary about their decision to move. She describes watching the water from the pond rise up on their former property during previous storms. On a few of these occasions, they received phone calls from the police department telling them to evacuate their home. “There were several reasons for wanting to leave, but we’d seen that image,” she says of the damage caused by storm surge and heavy rains. “And we weren’t very keen [on staying].”

Although the Stookeys had lived in and traveled to over a dozen cities and countries before settling in Newport 16 years ago, their latest move was the first to be influenced by changes in the local landscape–many of which are the result of the area’s geological and geographical features.

Newport, like many low-lying areas in Rhode Island faces challenges with rising seas and floods.

Part of the problem for Rhode Island is that the majority of its coastal zone is at sea level or only 10 to 30 feet above. These low-lying areas encompass not only residential homes, but also historic buildings, businesses, and important infrastructure (such as roads, bridges, hospitals, fire stations, and wastewater treatment facilities), as well as salt marshes that are vital habitats and buffers against wave energy and storm surge. The Stookeys’ former property reached roughly 10 feet above sea level at its highest point, making it highly vulnerable to an influx of rain or stormwater pouring from the 13 drains that filter into Almy Pond.

“It comes down to low-lying areas where you’re going to see huge areas inundated during storms and sea level rise,” says Bryan Oakley, a geoscientist at Eastern Connecticut State University investigating shoreline change in Rhode Island. He explains that some places—like Island Park on Aquidneck Island and Oakland Beach and Brushneck Cove in Warwick, as well as areas in Barrington, Warren, and Bristol—are especially vulnerable due to a combination of development and low elevation.

“They’re all sitting on glacial deltas, or stratified deposits of sand, gravel, and mud … if you look at deltas, wherever they are around the world, they tend to be flat, gently sloping landforms susceptible to inundation and sea level rise.”

Once the water rises a little, Oakley says, “it can go inland a pretty good distance.”

While some areas may be more vulnerable than others due to the extent they are developed, all of Rhode Island’s 21 coastal communities along the 400-mile stretch of coastline are vulnerable to inundation and wind-driven storm surge—even more so as sea levels continue to climb.

A 2017 report by the National Oceanic and Atmospheric Administration (NOAA) projects a greater increase in global sea levels than previously expected—up to 8 feet by the end of the century. The Northeast, however, is anticipated to experience an additional 1 to 3 feet on top of that projection.

In Wickford, 2 to 3 feet of sea level rise—expected by 2050—would put the town dock underwater and threaten over 100 properties collectively valued at $68 million to $95 million. Statewide, 3 to 5 feet of sea level rise would compromise almost 100 miles of roadway, an amount that doubles at 7 feet of rise. At that level, much of downtown Providence and the ports of Galilee, Quonset, and Providence would be underwater, and nearly 7,000 people living within the flood zone would be at risk, according to a recent Rhode Island Division of Planning report.

Add in storm surges and the problems get worse. During Superstorm Sandy, Rhode Island’s south coast was hit with storm surges reaching nearly 5 feet above normal high tide. In Providence, the storm surge height was 9.4 feet above sea level and 4.6 feet above normal high tide. Researchers are beginning to see the degree in which the shape of Narragansett Bay may be contributing to greater surge heights in specific areas.

In a recent pilot project by the Coastal Resources Management Council (CRMC) and the University of Rhode Island, researchers compared the state’s exposed southern shore with more protected areas in the upper bay region to assess differences in coastal vulnerabilities. They found that the narrowing of the bay northward toward Providence intensifies wind-driven storm surge, concentrating damage in isolated pockets, whereas surge would spread out more evenly over a greater geographic area along Rhode Island’s southern shoreline.

“It turns out there’s a 40 percent amplification from the mouth of the bay to the head of the bay … and almost no amplification as you go along the [southeastern] coast,” said Malcolm Spaulding, a professor emeritus of ocean engineering at URI, as reported by the Providence Journal, during a public meeting last summer. “I didn’t quite believe that until I started taking a look at the numbers, but sure enough.”

As storm surges are magnified with every foot gained in sea level rise, their effects will ripple throughout all coastal areas for the entire state.

“If NOAA is anywhere near right on this, it’s an order of magnitude faster than we’ve seen over the last century, and we’re already…seeing flooding in areas [like Newport] that have never flooded before,” says Oakley.

“To put it in perspective, we’ve had 10 inches [of sea level rise] during the last 90 years,” said Grover Fugate, executive director of Rhode Island’s CRMC, during a meeting with state energy and environment officials in February, according to a report by ecoRI news. “We’re potentially about to have 10 feet in the next 80 years.”

This added boost in local sea level is attributed to a combination of factors, according to Oakley. A warming climate is melting the Greenland and Arctic ice sheets, as well as weakening the Gulf Stream, which is drawing less water away from the East Coast.

And some places around the world, including Rhode Island, are sinking.

Although it has been over 20,000 years since Rhode Island was covered by ice, its effects remain present as the land slowly subsides.

The Laurentide Ice Sheet—a massive, mile-thick sheet of ice about the size of Antarctica—covered much of North America from Canada to Block Island and Long Island at its peak nearly 26,000 years ago. Its weight forced the Earth’s crust to sink into the underlying, more pliable mantle below, much in the same way a cargo ship would when loaded. The more fluid mantle material then flowed outward, underneath the Earth’s crust, toward the edge of the ice sheet, forming a peripheral bulge, elevating the surrounding landscape. But as the ice retreated, removing the load from the Earth’s surface, the mantle material that had flowed outward began flowing back, causing those areas that were once elevated to drop back down.

“That’s what’s happening now for Rhode Island. We’re on that peripheral bulge,” says Simon Engelhart, a geoscientist at URI investigating past changes in sea levels and concurring land subsidence.

He explains that while the peak of the bulge is in New Jersey, Delaware, and Maryland, where the land is sinking at a greater rate of 1.5 millimeters per year, Rhode Island is still losing about one millimeter annually based on measurements from a GPS installed on the URI campus. This subtle sinking, which could continue for tens of thousands of years before leveling out, may seem minimal compared to projected sea levels, but is still a significant contributor to sea level rise at present.

“[Land subsidence] is going to be important in the short term even though it’s small because it’s still a component of what we’re seeing,” he says, referring to “nuisance flooding.” These events, which are expected to increase with sea level rise, can cause road closures, overwhelm storm drains, and damage surrounding infrastructure. “The Newport tide gauge [measures] about 2.7 millimeters per year of relative sea level rise since it was started in 1930. A little more than a third of that is coming from land subsidence.”

Not only is the land sinking, it is also retreating landward. Coastal environments are naturally in a constant state of change as breaking waves, wind, tides, and currents move sediment from one place to another. Both salt marshes and beaches have the tendency to move toward the land behind them due to storm direction and sea level rise. But when the land is developed, this process is blocked, leading to a loss of shoreline and of the salt marshes that protect inland areas from storm surges and absorb floodwaters from heavy rain.

Rhode Island has already lost more than half of its salt marshes due to development since the Industrial Revolution, and this loss is continuing at alarming rates. Sediment is crucial to maintaining their elevation, says Engelhart, noting that salt marshes have been able to keep pace with land subsidence rates but not accelerated sea levels.

“Wetlands can’t produce organic matter, or wetland peat, quick enough to allow them to maintain their position,” he says. But Oakley stresses that it’s more of an issue of space. “If you give [salt marshes] space, the hope is that they can keep up with sea level rise and migrate because they like to be at that certain elevation of water,” he says. “The challenge is [when there is] developed property, seawalls, or roads [behind them], and so they don’t have the space to continue to migrate.”

The barrier beach that is Napatree Point in Westerly has moved 250 feet landward since 1939.

Oakley argues the same is true for barrier beaches, pointing to Napatree Point as a good example of a naturally evolving beach barrier. This 1.5-mile sandy spit along Rhode Island’s southern shore in Westerly that separates Little Narragansett Bay from the Atlantic Ocean has been pushed about 250 feet landward (toward Little Narragansett Bay) since 1939 via storm surge overwash and deposition of washover fans during hurricanes.

“Barriers are resilient landforms and are formed by the same processes that modify them. The things that are problems for people on barriers—storm surge and overwash—are the same things that form these land forms,” he says. “If you allow them to operate, barriers will be OK. They’ll move, they’ll migrate, and faster with sea level rise, but they’ll probably still exist as long as we leave them alone.”

Unfortunately, coastal communities draw hard lines in shifting sand.

“In terms of erosion, the most vulnerable spots are the south shore. It’s a combination of geology and where it’s developed,” says Oakley, citing Matunuck and Misquamicut as two of the most vulnerable areas in the state due to a combination of infrastructure, low elevation, and high erosion rates.

“Both are eroding glacial headlands—land that can erode relatively easily,” he says, noting how they behave more like barriers and experience higher erosion rates than other areas along the south shore.

“[Matunuck] is subject to a lot of erosion for reasons we don’t have the definitive answers for. We have some speculation and some ideas, but it’s certainly a combination of the right elevation, the right wave focus, and the right conditions to have a high rate of shoreline change—approaching 5 feet per year at South Kingstown Town Beach.”

Although the lowest points are still going to be the most vulnerable due to inundation and overwash, the bluffs on Block Island are made of similar material and just as vulnerable to erosion.

“The bluffs will continue to erode no matter what we do with sea level rise because waves can reach the base of the bluff and undercut and cause erosion,” Oakley says. “But there isn’t a ton of development right on those places where you’d see massive loss of infrastructure from the bluffs eroding. And the benefit of the bluffs eroding is providing a source of sediment for the beaches. Even though it’s high wave energy, the east side of Block Island and parts of the south side have low erosion rates comparatively because they’re getting fed by the sediment coming from the bluffs.”

Then there are headlands, such as Weekapaug Point, Green Hill Point, and Point Judith, that are made out of more resistant material called till—a mixture of clay and boulders left by the glacier. “They’re the ones that are more resistant and erode a little bit slower than the other headland and barriers,” he says.

But they, too, will erode. And the changes to the coastal landscape at large will challenge coastal communities to act.

“We’ve got to be able to adapt to this because all of these areas are going to see impacts faster,” says Oakley. “That’s a scary proposition, but it’s one we can deal with if we start to act and think about it now rather than [if we] keep dragging our feet.”

Since their move, David Stookey utilized his background in finance and spent three years writing the self-published book Climate-Proof Your Personal Financesas a way to help people start thinking about the costs associated with changes in the climate. “It’s looking for a moment to [act] even if you don’t have to because things aren’t that bad yet,” he says.

Stookey describes the ocean view from the bedroom window of their former home, joking that with one good storm, Bailey’s Beach, between Almy Pond and Narragansett Bay, would be gone, allowing them to sail directly out to sea. “Maybe we could’ve stayed there another 10 years,” he says with a shrug.

“We could see the ocean side of Bailey’s Beach from the upstairs of the house,” he says. “I would visualize a hurricane and think ‘this is not a good place to be.’”